<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <!-- 将数字转化成百分⽐格式 -->
    <script>
        var Num = prompt('请输入某个数字');
        var precnt  =  Number(Num / 100 )+'%';
        alert(precnt);
    </script>
</body>
</html>